I. Field
The following description relates generally to communication systems, and more particularly to a method and apparatus for acknowledgment detection during preamble transmission.
II. Background
In certain wireless systems, before two devices can communicate, they must be paired. The pairing process typically includes an acquisition process. Preamble sequences for wireless communications are used as part of the acquisition process. The purpose of the preamble is to allow time for the receiver in each wireless device to achieve lock of the receiver's Digital Phase Lock Loop, which is used to synchronize the receive data clock to the transmit data clock. At the point when the first bit of the preamble is received, each receiver may be in an arbitrary state. During the course of detecting the preamble, it learns the correct phase, but in doing so it may need to acquire a number of samples. Once the receiver has acquired the preamble, it will transmit an acknowledgement (ACK).
The wireless device may need to transmit multiple copies of a preamble before it receives an ACK from another wireless device. Once an ACK has been detected, the wireless device can then stop transmitting the preamble and then continue on to transmitting the payload. During the transmission of the preamble, the wireless device cannot receive an ACK. Thus, the process may be lengthy if the preamble is long and/or the duty cycle between the transmission of the preamble and waiting for the ACK is short.
Consequently, it would be desirable to address one or more of the deficiencies described above.